One example of such a kind of a game apparatus is disclosed in Japanese Patent Laying-open No. 7-155470. This game apparatus (referred to as a prior art 1) is a game apparatus in which a probability of continuing a game is determined based on a play time period, and a lottery is selected based on the determined probability at a time of ending a game play. Stored in this game apparatus are three kinds of lottery programs, that is, an amida-kuji (Japanese lottery to determine who pays how much, for example) having a winning probability of 1/10, a card-turning-up type lottery having a winning probability of 1/20, and a roulette having a winning probability of 1/40, for example, the lottery program corresponding to the determined probability based on the play time period is selected and executed, and an instruction to continue the game is delivered in a case of winning.
In addition, disclosed in Japanese Patent Laying-open No. 2002-248265 is an electronic roulette game. In this game apparatus (referred to as a prior art 2), the winning probability is changed by modifying the number of balls that move spots on a game board during the progress of the game.
In the prior art 1, the probability of a game-continuing lottery is merely changed, and in the prior art 2, too, the winning probability is merely changed. In neither prior art does a change of the winning probability affect progress and a content of the game later. Therefore, the game is tended to become simple, which leads to a problem that the game lacks an interesting aspect.